Abstract: Reverse-phase HPLC was applied to the determination of 4,4′-dicarboxy-2,2′-biquinoline (or named 2,2′-bicinchoninic acid,abbreviate as BCA) as a method of quality control in course of its production.The phenomenex-C18 column (4.6 mm×200 mm,5 μm) was used as the stationary phase and a mixture of methanol and 0.05 mol·L-1 NaOAc solution,mixed in the ratio of 3 to 7 by volume,was used as the mobile phase at a flow-rate of 0.5 mL·min-1,and with column temperature of 28 ℃.UV-detection was made at the wavelength of 330 nm.Linear relationship between values of peak area and concentration of BCA was obtained in the range of 0.05-10.00 mg·L-1.Seven sample of BCA taken from product of same batch,and contents of BCA were determined by the proposed method.The average content of BCA found was 98.62%,with value of RSD (n=7) to be 1.65%.